BACKGROUNDPatients with cystic fibrosis (CF) have significantly decreased plasma concentrations of nutrient antioxidant vitamins, especially of -carotene, which is thought to result from fat malabsorption and chronic pulmonary inflammation. The aim of this double blind, placebo controlled study was to investigate the effect of oral -carotene supplementation for six months on clinical parameters.
METHODSTwenty four patients with CF were randomised to receive -carotene 1 mg/kg/day (maximum 50 mg/day) for three months (high dose supplementation) and 10 mg/day for a further three months (low dose supplementation) or placebo. At monthly follow up visits the plasma -carotene concentration, total antioxidant capacity, malondialdehyde (MDA) as a marker of lipid peroxidation, and clinical parameters (Shwachmann-Kulczycki score, body mass index (BMI), height, and lung function (FEV₁)) were assessed. The number of pulmonary exacerbations requiring antibiotic treatment (in days) three months before and during the study were evaluated.
RESULTSThe plasma concentration of -carotene increased significantly to the normal range during the three months of high dose supplementation (baseline 0.08 (0.04) µmol/l to 0.56 (0.38) µmol/l; p<0.001) but decreased to 0.32 (0.19) µmol/l in the period of low dose supplementation. Initially raised plasma levels of MDA fell to normal levels and the total antioxidant capacity showed a non-significant trend towards improvement during high dose supplementation. Antibiotic treatment decreased significantly in the supplementation group from 14.5 (14.9) days/patient during the three months before the study to 9.8 (10.3) days/patient during high dose supplementation (p=0.0368) and to 10.5 (9.9) days/patient during low dose supplementation, but increased in the placebo group. The Shwachmann-Kulczycki score, lung function, and BMI did not show any changes in either of the treatment groups. No adverse events were observed during the study period.
CONCLUSIONOral -carotene supplementation in a dose of 1 mg/kg/day only was effective in normalising the plasma concentration of -carotene and resulted in a decrease in pulmonary exacerbations. These data suggest that patients with CF may benefit clinically from supplementation with -carotene and further studies are warranted.


Keywords: cystic fibrosis; -carotene supplementation; pulmonary exacerbations; clinical parameters; lung function